Pile and method of installing

Abstract

A method for installing a pile, in particular a monopile for a wind turbine, in a soil, comprising the method steps: —driving the pile into the soil using a vibration device; and—compacting soil material surrounding a lateral surface of the pile.

Claims

1. A method for installing a pile having a bottom, comprising a hollow monopile, for a wind turbine in soil, the method comprising: driving the hollow monopile into the soil using a vibration device, the hollow monopile having a bottom with an open end face disposed at a lowermost point of the pile; compacting soil material surrounding at least a section of a lateral surface of the hollow monopile; and wherein the compacting of the soil material surrounding at least the section of the lateral surface of the hollow monopile further comprises mechanically compacting the soil material by at least one of driving a collar coupled to the monopile into the soil or driving a local increase in diameter of the pile into the soil, and wherein the method further comprises injecting a fluid mixed with a filler into the soil at the lowermost point of the pile by at least one pipe that is disposed within the hollow monopile and extends up to the lowermost point of the pile.

2. The method according to claim 1, further comprising: decreasing an excitation frequency of the vibration device while at least one of the collar or the local increase in diameter is being driven into the soil.

3. The method according to claim 1, further comprising: changing a particle size distribution of the soil material with the fluid mixed with the filler.

4. The method according to claim 1, wherein: the filler includes particles having a diameter of 0.25 mm or less; and/or the filler comprises at least one of sand, cement or bentonite, or consists of at least one of sand, cement or bentonite.

5. The method according to claim 1, wherein: the at least one pipe is attached to the monopile.

6. The method according to claim 1, further comprising: loosening and/or liquefying the soil material surrounding the lateral surface of the monopile prior to the compacting of the soil material surrounding the lateral surface of the monopile.

7. A pile having a bottom, comprising: a hollow monopile having a bottom with an open end face disposed at a lowermost point of the pile; at least one of a collar coupled to the monopile or a local increase in diameter of the pile, configured to mechanically compact soil material, wherein the at least one of the collar or the local increase in diameter surrounds at least a section of a lateral surface thereof; and at least one pipe attached to the monopile, which is configured to inject a fluid mixed with a filler into soil at the lowermost point of the pile, wherein the at least one pipe is disposed within the hollow monopile and extends up to the lowermost point of the pile.

8. The pile according to claim 7, wherein: the at least one of the collar or the local increase in diameter is configured to be at least partially seated in soil when the pile is fully mounted.

9. The pile according to claim 7, wherein: a distance between an end face of the pile to be sunk into soil and the at least one of the collar or the local increase in diameter is 15 m or more.

10. The pile according to claim 7, wherein: the at least one of the collar or the local increase in diameter has an axial length of 1 m to 5 m.

11. The pile according to claim 7, wherein: the monopile has a circular hollow profile.

12. The pile according to claim 7, wherein: the monopile comprises a steel pipe.

13. The pile according to claim 7, wherein: the collar is wedge-shaped.

14. The pile according to claim 7, wherein: at least one of the collar or the at least one pipe is/are welded to the monopile.

15. The pile according to claim 7, wherein: the at least one of a collar coupled to the monopile or a local increase in diameter of the pile comprises the collar coupled to the monopile; and the lateral surface of the monopile is an outer circumferential surface of the monopile; and the collar extends circumferentially around at least a section of the outer circumferential surface of the monopile.

16. The pile according to claim 15, wherein: the collar comprises an annular ring.

17. The pile according to claim 15, wherein: the collar extends circumferentially around the outer circumferential surface of the monopile in a closed loop.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in greater detail hereafter based on a drawing showing exemplary embodiments. The drawings in each case show schematic illustrations:

(2) FIG. 1 shows a pile according to the invention in a top view and a longitudinal view;

(3) FIG. 2 shows the pile from FIG. 1 in a top view and a longitudinal view;

(4) FIG. 3 shows another pile according to the invention in a top view and a longitudinal view;

(5) FIG. 4 shows a diagram for changing the particle size distribution;

(6) FIG. 5 shows another pile according to the invention in a top view and a longitudinal view;

(7) FIG. 6 shows another pile according to the invention in a top view and a longitudinal view.

DETAILED DESCRIPTION

(8) FIG. 1 shows a pile 2 according to the invention in a top view and a longitudinal view.

(9) The pile 2 is a monopile for a wind turbine. So as to improve clarity, only the portion of the monopile assigned to the soil 4 is shown.

(10) The pile 2 includes a collar 6 for mechanically compacting soil material 8 of the soil 4. The collar 6 completely surrounds a lateral surface 12 formed on a wall 10 of the pile 2 on the circumference. According to alternative exemplary embodiments, it may be provided that the collar comprises a plurality of mutually spaced segments.

(11) In the fully mounted state of the pile 2 shown in FIG. 1, the collar 6 is partially seated in the soil 4 in which the pile 2 is installed. In the present example, the collar 6 is welded to the wall 10 of the pile 2 in the region of the outer lateral surface 12.

(12) In the shown example, a distance a between an end face 14 of the pile to be sunk into the soil 4 and the collar 6 is more than 15 m. In the present example, the collar 6 has an axial length b of 3 m. In the present example, the pile 2 is a substantially circular hollow profile made of steel. In the present example, the distance a and the length b are measured parallel to or along a driving direction R which, in turn, extends parallel to or along a longitudinal axis L of the pile 2.

(13) So as to install the pile 2 in the soil 4, the pile 2 is initially driven or placed by vibration into the soil 4 using a vibration device 16. As soon as the collar 6 makes contact with the soil 4 as the pile 2 is being driven along the driving direction R, soil material is compacted in a compaction region 18 adjoining the collar 6 and the lateral surface 12. In a loosening region 20 adjoining the compaction region 18, the soil material 8 remains in the loosened state created by the vibrations of the pile 2.

(14) Prior to the compaction of the soil material 8 surrounding the lateral surface 12 of the pile 2, the soil material 8 thus is loosened and/or liquefied by the vibrations of the pile 2 generated by way of the vibration device 16.

(15) So as to support the compaction of the soil material 8 in the compaction region 18 and increase the axial length of the compaction region 18, an excitation frequency of the vibration device 16 can be decreased while the collar 6 is being driven into the soil 4. This yields the increased compaction region 18 shown in FIG. 2.

(16) FIG. 3 shows an alternative design according to the invention of a pile 22. The pile 22 is again a monopile 22 for a wind turbine, which is shown in a top view and a longitudinal view.

(17) The pile 22 includes four pipes 26 attached to an inner lateral surface 24 of the pile 22. The pipes 26 are configured to inject a fluid 28 mixed with a filler into a soil 30. The pipes 26 are welded to the inner lateral surface 24. The injection of the fluid 28 mixed with filler into the soil 30 is carried out, in particular, in the region of an end face 38 of the pile 22 driven into the soil.

(18) The filler entrained with the fluid 28 has particles that have a diameter of less than 0.25 mm. As a result of the introduction of the fluid 28 mixed with filler, a particle size distribution of a soil material 32 of the soil 30 is changed in a compaction region 34, wherein overall better graded material having enhanced compaction properties is created. In this way, compaction of the soil material 32 is achieved in the compaction region 34 adjoining an outer lateral surface 36, as indicated by the dotted line.

(19) FIG. 4 shows a particle distribution before and after the introduction of the fluid 28 mixed with filler by way of example. The solid line “new” describes the state after the introduction of the fluid 28 mixed with filler, while the dotted line “old” describes the particle size distribution before the introduction of the fluid mixed with filler. It is apparent that a shift of the distribution toward a wide gradation of the particle size has taken place.

(20) FIGS. 5 and 6 show further variants of piles 2, which differ from FIGS. 1 and 2 by a wedge shape of the collar 6.

(21) It shall be understood that the piping of the pile 22 shown in FIG. 3 can be combined with a collar 6 of the examples from FIG. 1, FIG. 2, FIG. 5 and FIG. 6, so that the advantages of mechanical compaction can be combined with the wide gradation of the particle size, in particular the introduction of an additive such as sand, bentonite or cement, so as to increase a lateral bearing capacity of a pile.

REFERENCE NUMERALS

(22) 2 pile 4 soil 6 collar 8 soil material 10 wall 12 lateral surface 14 end face 16 vibration device 18 compaction region 20 loosening region 22 pile 24 inner lateral surface 26 pipe 28 fluid (mixed with filler) 30 soil 32 soil material 34 compaction region a distance b length L longitudinal axis R driving direction